Process of applying compound paper gaskets



June 18, 1929. s, CLARK 7 1,717,664

PROCESS OF APPLYING COMPOUND PAPER GASKETS Filed April 4, 1921IIIIIIIIIII Patented June 18, 1929.-

UNITED STATES v V r 1,717,664 PATENT OFFICE.

BERTON s. cLAEK, or HAYWOOD, ILLINOIS, AssIeNoE r AMERICAN CAN COMPANY,

on NEW YORK, N. Y., A CORPORATION on NEW JERSEY.

PROCESS OF APPLYING COMPOUND PAPER GASKETS.

Application filed April 4,

This invention relates in general to can end seams, and has moreparticular reference to the provision of a gasket to be included in theseam of a sanitary can which will insure,

in greater degree than has been heretofore p0ssible,'the production ofhermetic seam- The cans referred to are of the sanitary character inwhich no solder is employed 1 in the seaming, complete sealing beingsought through the tight. interfolding of flanges upon the end and body"with an interposed gasket. Cans of this character are used largely inthe-packaging of food products and are completely processed and seamedto provide a vacuum within the can as an incident to the cooling andcondensation of the contents, which vacuum must be preserved to insureagainst spoilage. So long as the vacuum be maintained germ-laden aircannot enter the can to start fermentation or decay.

In the past two characters of gaskets have been employed, namely: acompound of rubber material, and a fibre or paper ring, and eachrequires extreme accuracy of setting of the seaming rolls, and even whenthe seaming rolls are accurately set a small percentage of leaks occur.

The invention has for its principal object the provision of a, gasketfor this purpose,

which will reduce the leakage to a minimum 7 and which will not requirethe now necessary accuracy of roll adjustment. In this connection it isto be remembered that in the manufacture of tin cans for the packingof'food products and for-other purposes one end of the can is secured tothe body at the can factory and the other by closing ma- 40 chinesoperated by packers themselves and these packers frequently lackoperatives highly skilled in the handling of the closing machines andparticularly in the maintenance of roll adjustment. 7

A frequent source of can leakage occurs on account of the slightwrinkling -of the edge of the can cover when it is curled around theflange of the can body by the interfolding action of the seam formingroller. This wrinkling is present to some extent in almost all seams andthe little ridges formed thereby tend to press unevenly on the papergasket if they are not completely ironed out in th"e final rollingoperation which fully o5 closes and completes the interfolding of the1921. serialNo. 458,623.

pressibility but will prevent it from flowing under the pressurenecessary to roperly close the seams in which it is used. Ey beingcompressible and resilient and not having a tendency to flow underpressure, it willbe placed under a tension when enclosed in a doubleseam and will thus have a tendency to continually conform itself to thespaces in the seam and follow their contraction and expansion if thereis any, and always thereby maintain a hermetic seal. The material thatseems the best from present practice and advice is of a wood pulp orpaper fibre nature combined with a compound of a character similar tothat already in use.

Another object of the invention is the r provision of a material of thischaracter, but sufliciently fluid in its preparation to be handled inthe ordinar compound lining machines now in use for ining can ends withthe ordinary compound, and to be dried in the machines now used fordrying lined ends, so that its advantages may be obtained without thenecessity of replacing already installed equipment. Numerous otherobjects and advantages of the invention will be a parent as it is betterunderstood from the ollowing description, which, taken in connectionwith the accompanying drawings, discloses a preferred embodimentthereof.

Referring to the drawing,

Figure 1 is a top plan view of a lined 100 car:1 end embodying mypresent invention; an

Fig. 2 is an enlarged section on the lin 22 of the same.

The compound selected as an embodiment I of the invention is shown at 10on the usual flange 11 of the can end 12.

This compound itself has the usual roperties of the compound heretoforeemp oyed in lining can ends. The basis for this-is particles from whichthe rubber and wood particles may be deposited upon the can end withoutrequiring too great drying effort. I have found that a suitableemulsifier having a unit formula as follows is effective :To 100 cubiccentimeters of water is added 5 grams of zinc chloride, and 20 cubiccentimeters of ammonium hydroxide. To this emulsifier is added 50 cubiccentimeters of benzole and 300 cubic centimeters of.6% rubber solution.To this is added the wood fibre to the amount of from probably to gramsof 60 mesh fibre wood screenings, the whole is thoroughly shaken and itwill be found that the wood fibres stay in suspended condition. The'zinc chloride and the rubber form a colloidal solution and it isbelieved that through colloidal action they hold the wood fibres insuspended emulsified condition in the liquid. The liquid has a specificgravity less than the wood. This material may be applied to the flangeof the can end in theprdinary compound lining machine and the cans thuslined may be passed through the drier of a lining machine and stackedaway for a few days in the open air to season. After the liquid contentsof the emulsion have evaporated the desired gasket composed of therubber constituents and the fibrous material remains in the can end andforms the desired gasket.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and.

it will be apparent that various changes may be made in the formulasabove set forth for the purposes of illustration without departing fromthe spirit and scope of the inven tion or-sacrificing all of itsmaterial advantages, the form hereinbefore described being merely apreferred embodiment thereof.

I claim:

1. A flange lining material for forming a gasket to be included betweeninterfolded flanges in the formation of an hermetic double seam betweena flanged can end and a flanged can body, comprising an emulsifiedrubber solution, containing fibres, and zinc chloride.

2. A flange lining material for formin a gasket to be included betweeninterfol ed flanges in the formation of an hermetic double s'eam betweena flanged can end and a flanged can body, comprising a rubber solution,wood fibres, and zinc chloride.

3. The process of preparing can ends for hermetic sealing, whichconsists in making an emulsion containing water, zinc chloride,

ammonium hydroxide, benzole, rubber and fibrous materiahapplying theemulsion t0 the sealing portions of the can ends, and drying theemulsion.

BERTON s. CLARK.

